Flare drill



April 14, 1953 w.`E. coYLE FLARE DRILL Filed July 51, 1950 5 Sheets-Sheel l ATTORNEYS w. E. coYLE 2,634,957

April 14, 1953 v FLARE DRILL 5 Sheets-Sheel 2 jlgf4. /7

Filed July 51, 1950 Tf/ J Z/-f l...

f y-g April 14, 1953 l w, E COYLE 2,634,957

' FLARE DRILL Filed July 31, 1950 3 Sheets-Shee. 5

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Patented Apr. 14, 1953 UNITED STATES PATENT OFFICE 2,634,95@ FLARE DRILL William Coyle, Cotton Valley, Application July 31, 1950, Serial No.' 1-76,8l'8

4 claims. (o1. 2st-s6) v This invention relates to an expansion drill particularly suited for expanding drill holes in oil, water, or gas formations.

One important object .of the present invention is to provide a drill of the type stated expandable Within the drill hole in a manner to drill out larger openings in productive formations.

Another object is to provide a drill of the character described expandable by pressure applied through the medium of a piston, and equipped with a means for relieving said pressure when the drill cutters hang up on the wall of the drill hole or are receiving too much pressure.

Another important object is to provide a drill of the character described wherein the pressure applied through the medium of the piston causes normally flattened longitudinally extended spring cutters to be bowed outwardly radially of the drill in a manner to engage and enlarge the wall of the previously drilled hole.

With the foregoing and other objects in View which will appear as the description proceeds. the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claims, it being understood that changes maybe made in the construction andarra'ngement of parts without departing from the spirit of the 'invention as claimed.

Referring to the drawings Figure 1 is a side elevational View of a drill formed in accordance with the present invention, the cutters being illustrated in their straightened or inoperative position.

Fig. 2 is a similar view, the cutters being bowed outwardly to operative position.

Fig. 3 is an enlarged section taken substantiaily online 3;-3 of Fig. 1.

Fig. 4 is Van enlarged longitudinal section through the lower portion of the drill, vportions being broken away. K

Fig. 5 is a section taken' on line 5-5 of Fig. 4.

Fig. 6 is a section on line 6-- of Fig. 3..

Fig. '1 is a section on line 'I-l of Fig. 4.

Fig. '8 is a sectiony on line a-s of Fig. 3. v

Referring to the 4drawings in detail, apiston cylinder l is threaded at its upper end for cori-V nectin to a pipe section 2 said pipe section be ing the iowermost section of the drill pipe which, es will be understood, extends upwardly to the surface'. r,

Reciprocable within the piston cylinder I -is the piston 3 and overlying the piston is the 2 ywasher valve 4 having the diametrically opposed slotted` openings 5 which are adapted to be brought into and out of register with diametrically opposed circular openings 6 formed in the piston.

1As illustrated in Fig. 6 the walls of these openings 5 are elongated and the side walls thereof converge -so that the openings taper in opposite directions. n

Extending through the center of the piston is a hollow shaft 'I on which the .piston has up' and down sliding movement when the piston slides upwardly and downwardly within the piston cylinder I. The upper end portion of the shaft 1 has the elongated longitudinal keyway 8, for the reception of a tongue 4 carried by the washer valve 4, which slides upwardly and downwardly with the piston, but is held against rotation relative to the hollow shaft. The piston itself, however, can rotate relative to said hollow shaft. r

The lower end of the piston is formed as a pressure plate 9, and connecting the top end of said piston 3 to said pressure plate 9 is the cylindrical sidewall I9 defining a hollow chamber with the piston and the pressure'plate. A tubular shaft 1 extends through the piston 3 and the pressure plate 9 axially through the chamber and the bore of the shaft is an opening II formed in the shaft.

Diametrically opposed longitudinal slots I2 are provided in the lower end portion of the cyl- :InderI I and sliding in these slots are outwardly extending diametrically opposed lugs I3 carried bythe pressure plate 9. The lugs I3 bearagainst a spacer sleeve I4 that surrounds the lower end of the cylinder I. Therefore, downward moveinent of the piston carries with it the spacer sleeve I4. The lower Aend of the cylinder I has' an annular inturned flange I5 on which seats an octag'onal plate IB which is threadedly connected. to the lower end of the hollow shaft 'I and carries a depending' hollow circular sleeve I'I.

'Surrounding the sleeve I1 isa torque spring 8, one end of which is engagedby a depending lug I9 carried by thevlower end of the cylinder I. `The other end of the spring I8 abuts an outwardly extending lug 20 carried by said sleeve I1 carried by the sleeve and depending from the lower end thereof is a hollow drive shaft 2l which is square in cross section. Slidable on the portion of the shaft 2| adjacent the sleeve I1 is a movable upper collar 22 having a pluf. iality of pairs of ears 23 here shown as four in number. A fixed bottom collar 24 is rigidly secured to the lower end of the shaft 2| and has ears 25. Extending between the ears 23 are connecting pins 26 on which are pivotally mounted the upper ends of elongated longitudinally extended cutters 21 of spring material having the cutting teeth 28 formed on their outer surfaces. The lower ends of said cutters are pivoted upon cross pins '29 extending between the ears 25.

Spaced from top to bottom of the hollow drive shaft 2| are uid circulation openings 30, that are continuously open. A bottom circulation opening 3| is normally clpsed by a ball valve 32, mounted upon the pivoted arm 33, which is pivotally mounted intermediate its ends upon the lower end portion of the shaft 2|. To the other end of the arm 33 is pivotally connected the valve release rod 34 extending longitudinally adjacent the shaft 2|, and slidable at its other end in the collar 36 secured toan intermediate portion of said shaft. Spring 35 surrounds the upper end of said valve release rod 34, and normallyholds the ball valve 32 seated in position to close the opening 3|.

In use, the drill is lowered into a previously drilled small drill hole, with the cutters in the position shown in Fig. l and the openings 5 and 6 in the washer valve 4 and piston 3 out of registry. When it is desired to begin expanding the drill hole, fluid pressure is applied through the drill pipe sections to the top of the cylinder' While the drill pipe 2 and the cylinder are being rotated. Since the cylinder is being rotated, the piston will also be rotated with the cylinder since the lower end of the piston is provided with the lugs |3 that extendthrough slots in the cylinder The piston, of course, also has up and down movement relative to said cylinder.

As the piston moves downwardly, the lugs I3 will press downwardly the spacer sleeve 4 which, it may be noted, is not rotated directly by the cylinder Thelower end of the spacer sleeve |4 bears against the upper collar 22 to which the upper ends of the springable cutters 21 are connected. This forces the collar 22 downwardly. As a result, the cutters 21 will be bowed outwardly as in Fig. 2, and will expand into contact with the walls of the opening to be expanded, and the cutters 28 will then scrape away the sides of said drill hole, thus to expand the hole substantially.

As will be appreciated, the outwardly bowed cutters 21 rotate for the purpose of expanding the drill hole. In this connection, it may be noted that rotation of the cylinder causes rotation of the spring E8 by reason of the lug |9 of the cylinder that engages the upper end of the spring. The spring I8 will in turn engage the lug 20 on the upper end of the drive shaft 2 rotating said drive shaft and, as a result, the cutters 21. During normal operation of the device, the piston will be forced downwardly and will be held in its lower position by the pressure thereupon, permitting regular operation of the drill. However, assuming that the cutters 21 might hang up upon some obstruction encountered thereby, resistance to rotation initiated by the hung cutters will be transmitted by the lug 20 to the spring I8 causing the spring to yield. Continued rotation of the cylinder causes the spring I8 to transmit rotary motion to the hollow shaft 1 by Way of the lug I9 and as a result, the washer valve 4 will rotate relative to the piston 3 so as to bring the large portions of the slot 5 of the washer valve 4 into registry with the openings 6 of the piston. The pressure upon the piston will be thereby relieved '4 as the fluid may escape through the openings 6 in the upper end of the piston into the chamber and thence downwardly through ythe opening in the hollow shaft 1 and into the well hole through the slots |2 and the uid circulation openings 30 of the drive shaft 2|.

Relief of pressure upon the piston immediately causes the piston to move upwardly, flattening out the cutters 21 so that the cutters 21 are freed from any obstruction on which they may have become hung.

It will be understood that the reason for forming the slots of the washer valve as illustrated is to allow the flow of fluid through the registering slots and piston openings to become larger as the hollow shaft moves into position where the slots and openings begin to register.

In the upper end of the hollow shaft 1 is mounted a check valve 31, which allows circulating fluid to pass downwardly through the hollow shaft and through the circulation openings 30 when the device is not rotating, thus to permit clearance of or circulation of the cuttings to allow for further rotation of the tool. The check valve opens above a predetermined pressure.

Referring to the ball valve 32, this is opened whenever the collar 22 is moved downwardly to a position in which it will engage the upper end of the valve release rod 34. As a result, the ball valve 32 is lifted offV its seat, so that pressure is directed through the bottom opening so as to clear the drill hole immediately below the dee vice for further use of the device.

What is claimed is:

l. In an expansion drill for enlarging a well hole below the surface of the ground said drill being of the type employing elongated cutters adapted to be bowed outwardly into contact with the wall of a Well hole and rotated in contact therewith, means for rotating said cutters and bowing them into contact with the wall of the well hole comprising, a cylinder adapted to be rotated Within a well hole, a piston working within said cylinder and operatively connected to the cutters for bowing them outwardly as it advances within the cylinder, means for introducing fluid under pressure into said cylinder to advance the piston, a pressure relief valve carried by the piston, yielding means carried by the cylinder and operatively connected to the cutters for establishing rotary driving connectionbetween the cylinder and the cutters, and means operatively connected to the cutters and to the pressure relief valve for opening said valve and permitting the escape of fluid from the cylinder when the resistance of the cutters to turning attains a predetermined value.

2. The structure recited in claim 1 in which the piston has openings extending longitudinally therethrough, the pressure relief valve comprises a disk mounted on the piston to rotate'about the longitudinal axis thereof, and said disk has openings extending therethrough which in one position of the disk register with the openings in the piston.

3. In an expansion drill, an elongated :duid pressure conduit mounted to rotate about its longitudinal axis within a well hole, a piston mounted in the conduit to move longitudinally and to rotate therewith adjacent the end thereof adjacent the bottom of the well hole, a cutter drive shaft carried by the conduit for rotation relative thereto, said drive shaft projecting longitudinally from the conduit toward the bottom of the Well hole, a collar carried by the cutter drive shaft for movement longitudinally thereon adjacent they conduit, circumferentially spaced outwardly bowable cutters carried by the cutter drive shaft and connected to the collar, a tortion spring carried by the drive shaft and operatively engaging the conduit and the drive shaft for rotating the drive shaft when the conduit is rotated, means carried by the collar and operatively connected to the piston for moving the collar longitudinally on the drive shaft and bowing the cutters when uid entering the conduit exerts pressure on the piston, a pressure relief valve carried by the piston, and means operatively connected to the drive shaft and to said pressure relief valve for opening said valve and permitting the escape of fluid pressure-from the conduit when resistance to the turningjof the drive shaft by the spring attains a predetermined value. y

4. In an expansion drill for enlarging a well hole below the surface of the ground, an elongated cylinder mounted in the well hole for rotation about its axis, an elongated cutter drive shaft carried by the cylinder and projecting longitudinally therefrom, said cutter drive shaft being rotatable relative to the cylinder about the axis thereof, a piston mounted Within the cylinder for movement under the influence of fluid pressure within the cylinder, circumferentially spaced outwardly bowable cutters carried by the drive shaft and operably connected to the piston, said cutters being adapted to be bowed outwardly as the piston advances toward the cutter drive shaft under the influence of uid pressure within the cylinder, a pressure relief valve carried by the piston and operatively connected to the cutter drive shaft for permitting the escape of fluid from the cylinder when the cutters resist turning, and yielding means carried by the drive shaft and operatively engaging the cylinder for yieldingly holding the valve closed and establishing driving connection between the cylinder and the drive shaft.

WILLIAM E. COYLE.

References cited in the me of this patent UNITED STATES PATENTS Number Name Date 1,402,503 Krause Jan. 3, 1922 1,402,786 Muehl Jan. 10, 1922 1,823,367 Lorenz Sept. 15, 1931 2,116,903 McClatche et a1. May 10, 1938 2,284,170 Santiago May 26, 1942 2,450,223 Barbour Sept. 28, 1948 

